1. Field of the Invention
This invention relates generally to a cable reeler and more particularly to a cable reeler for continuously maintaining a length of cable in a taut condition.
Cable reeling drums are used extensively to carry cable for transmitting electrical, pneumatic or hydraulic power to mobile equipment from a fixed power source. The drums are also used for reeling hose, rope and other elongated flexible materials (hereinafter referred to generally as cable) when it is important that trailing lengths of the cable are not left lying loosely about where they can be damaged, tangled, or obstruct workmen and equipment. A rotatable drum is used to pay out or wind in cable as required, depending upon the operating position of the equipment relative to the source to which the end of the cable is connected.
2. Description of the Prior Art
Known cable reeling drums include a central coupling so that a commodity can be transferred from a cable connected to a stationary source to the cable on the rotatable drum. In the case of an electric cable, for example, there may be several individual cores and the coupling is in the form of a slip ring. This permits the transfer of electric current or a signal from each core in the fixed cable to the complementary core in the cable on the drum. In the case of a hydraulic hose, a fluid tight rotary seal at the end will ensure that fluid is transferred without leakage. Known cable reeling drums are rotated by a motor, and if the drum has a substantial width, the cable must be evenly distributed back and forth across the width of the drum as it is wound thereon or removed therefrom. This is normally achieved with a cable distribution arm having a guide through which the cable passes, and which is moved automatically across the width of the drum as the drum rotates. The arm is normally mounted on a rotatable spindle which is mounted to extend across the width of the drum parallel to the axis of rotation of the drum and is spaced from the drum by a distance slightly more than the maximum drum radius. The distribution arm is moved across the width of the drum by a pair of opposed helices formed in the surface of the rotatable spindle, which are engaged by a complimentary sleeve-like follower on the arm. A drive such as a sprocket and a chain is provided to rotate the spindle with the drum, and when the distribution arm reaches one end of the spindle, it automatically engages the opposed helix, and starts to move back across the width of cable of the drum. This arrangement ensures that the cable is carefully laid onto the drum, on top of any cable which is already wound thereon. This distribution arrangement is well-known to those skilled in the art and is similar to a pump action screwdriver (but in reverse).
While known cable reeling drums are satisfactory, their capacity is limited by their width and diameter. For example, in underground mines, there is often a rigid constraint on the height of the equipment, and yet it may be necessary to operate a mining machine a considerable distance from a power source. This requires a very high capacity cable reeler. Due to the height constraint and other space constraints on the size of the mining machine, it may be impossible to use a known cable reeling drum.